Abstract: A battery system may include a plurality of subdivisions, such as battery cells or sub-packs. A measurement system configured to determine a subdivision electrical parameter associated with each of a plurality of subdivisions. A battery control may identify a subdivision satisfying a criterion based on the plurality of subdivision electrical parameters. According to some embodiments, the battery control system may determine a ratio of the subdivision electrical parameter of the identified subdivision to the electrical parameter of the battery pack. The ratio may be used to scale the electrical parameter associated with the battery pack by the ratio. According to other embodiments, the subdivision electrical parameter associated with the identified subdivision may be provided to a battery state estimation system. The scaled electrical parameter or the electrical parameter associated with the identified subdivision may be used by a battery state estimation system to generate an estimated battery state.

Abstract: A method for modeling changes in the state of charge vs. open circuit voltage (SOC-OCV) curve for a lithium-ion battery cell as it ages. During battery pack charging, voltage and current data are gathered for a battery cell. A set of state equations are used to determine the stoichiometry and state of charge of the cathode half-cell based on the charging current profile over time. The voltage and current data, along with the stoichiometry and state of charge of the cathode half-cell, are then used to estimate maximum and minimum solid concentration values at the anode, using an error function parameter regression/optimization. With stoichiometric conditions at both the cathode and anode calculated, the cell's capacity and a new SOC-OCV curve can be determined.

Abstract: A method of determining a state of health of a battery in real time includes estimating a parameter value associated with the state of health of the battery and determining one or more of a terminal voltage, an accumulated charge, a state of charge, and a temperature of the battery. The method further includes determining, via a computing device, a reserve capacity of the battery based at least in part on the estimated parameter value and one or more of the terminal voltage, the accumulated charge, the state of charge, and the temperature of the battery.

Abstract: Methods and systems are provided for characterizing a battery. A property of the battery is measured. A dynamic characteristic of the battery is determined from a second order linear dynamic model.

Abstract: A method for estimating the capacity of a vehicle battery while in service. The method includes providing a previous battery state-of-charge, battery temperature and integrated battery current amp-hours, and determining that battery contactors have been closed after they have been opened and disconnected from a load. The method determines if the battery has been at rest for a long enough period of time while the contactors were open, where the battery rest time is based on battery temperature, and determines an initial battery voltage from a last time step when the battery contactors were closed prior to the contactors being open during the battery rest time. The method determines a present battery state-of-charge from the initial battery voltage and the battery temperature and calculates the battery capacity based on the battery integrated current amp-hours divided by the difference between the present battery state-of-charge and the previous battery state-of-charge.

Abstract: A method and system for use with a vehicle battery pack having a number of individual battery cells, where the method estimates, extrapolates or otherwise determines individual cell resistances. According to an exemplary embodiment, the method and system use a voltage and temperature reading for each of the individual battery cells, as well as a voltage and current reading for the overall battery pack to determine one or more cell resistance values, such as a minimum and maximum cell resistance for the battery pack. This approach relies upon temperature deviations in the battery pack to make assumptions or estimates regarding individual battery cell resistances. By having individual cell resistance values—instead of using an overall pack resistance value and building in a buffer to account for cell variations—better and more accurate cell-level data can be obtained that, in turn, can improve charging, discharging, cell balancing and/or other battery-related processes.

Abstract: A method and system for manipulating, adjusting or otherwise controlling a state-of-charge (SOC) operating range for a high voltage vehicle battery, such as the type used for hybrid or electric vehicle propulsion. By providing a dynamic SOC operating range that changes in response to changing battery conditions, the battery performance may be improved so that the battery life is extended. Depending on the particular embodiment, the dynamic SOC operating range may have different combinations of hard and/or soft boundaries or limits.

Abstract: Methods and systems for determining a state of charge of a battery exhibiting a transient response are provided. At least one property of the battery is measured. The state of charge of the battery is determined based on the at least one measured property and a transient response of the battery.

Abstract: A hybrid control module comprises a vehicle load module and a hybrid battery discharge module. The vehicle load module determines a first power based on power delivered to an accessory power module (APM). The hybrid battery discharge module determines a discharge power based on the first power and selectively controls power consumed by an inverter based on the discharge power when a state of charge of a hybrid battery is less than a first threshold and greater than a second threshold. The inverter and the APM selectively receive power from the hybrid battery.

Abstract: A method and system for heating a vehicle battery, such as the type used for vehicle propulsion in a hybrid electric vehicle (HEV). Depending on the battery chemistry involved, such batteries may not perform well in extremely cold environments. For instance, a lithium-ion battery can exhibit a high internal resistance when the battery is extremely cold, which in turn can negatively affect the available power or other capabilities of the battery. According to an exemplary embodiment, the method and system take advantage of the high internal resistance in a cold vehicle battery by purposely cycling electrical current in and/or out of the battery so that heat is created. This heat warms up the vehicle battery and thereby improves its overall performance and capabilities.

Abstract: A method for use with a vehicle battery pack, where the method determines a voltage threshold that may prevent the vehicle battery pack from being overcharged. The voltage threshold may be a dynamic threshold that changes or adjusts over time in order to accommodate changing conditions in the vehicle battery pack, the vehicle and/or the surrounding environment. The method may consider one or more battery readings when determining the voltage threshold, including temperature, voltage and/or current readings. According to one embodiment, the method is designed to accommodate high-current, short-duration charging events, like regenerative breaking.

Abstract: A system and method for controlling a state-of-charge (SOC) of a vehicle battery, such as a high-voltage battery used by a hybrid electric vehicle (HEV) for vehicle propulsion, so that the SOC is maintained within a desired SOC range that is temperature-dependent. In an exemplary embodiment, the system and method use a battery temperature prediction to determine a desired SOC range, and then control the amount of charge on the vehicle battery such that the SOC is maintained within the desired SOC range. As the battery temperature prediction goes lower (i.e., as it gets colder), the desired SOC range may need to be adjusted or shifted upwards in order to account for increased internal battery resistance and to ensure that the vehicle battery has enough power to start the vehicle. Similarly, as the battery temperature prediction goes higher (i.e., as it gets warmer), the desired SOC range may need to be adjusted or shifted downwards in order to reduce degradation effects and improve battery.

Abstract: A computer implemented method of facilely releasing a BSE software module adapted for execution by an electronic control unit having an update model of the BSE software and a controller having an embedded desktop model of the BSE software, includes a plurality of autonomously performed steps resulting in the compiling of a plurality of c-files into a library file. A single keyword activated preferred embodiment is disclosed in a MatLab®/Simulink®/Real-Time Workshop® environment.

Abstract: A system and method for use with a vehicle battery pack having a number of individual battery cells, such as a lithium-ion battery commonly used in hybrid electric vehicles. In one embodiment, the method evaluates individual battery cells within a vehicle battery pack in order to obtain accurate estimates regarding their average transient voltage effect, open circuit voltage (OCVCell) and/or state of charge (SOCCell) so that a cell balancing process can be performed. These cell evaluations may be performed fairly soon after the vehicle is turned off and in a manner that utilizes a minimal amount of in-vehicle resources.

Abstract: A method for estimating the capacity of a vehicle battery while in service. The method includes providing a previous battery state-of-charge, battery temperature and integrated battery current amp-hours, and determining that battery contactors have been closed after they have been opened and disconnected from a load. The method determines if the battery has been at rest for a long enough period of time while the contactors were open, where the battery rest time is based on battery temperature, and determines an initial battery voltage from a last time step when the battery contactors were closed prior to the contactors being open during the battery rest time. The method determines a present battery state-of-charge from the initial battery voltage and the battery temperature and calculates the battery capacity based on the battery integrated current amp-hours divided by the difference between the present battery state-of-charge and the previous battery state-of-charge.

Abstract: A method of determining a state of health of a battery in real time includes estimating a parameter value associated with the state of health of the battery and determining one or more of a terminal voltage, an accumulated charge, a state of charge, and a temperature of the battery. The method further includes determining, via a computing device, a reserve capacity of the battery based at least in part on the estimated parameter value and one or more of the terminal voltage, the accumulated charge, the state of charge, and the temperature of the battery.

Abstract: A method of controlling a vehicle powertrain and a corresponding vehicle control system are provided that enable operation in an electric-only operating mode for an extended range by adjusting the threshold minimum state of charge of the battery, i.e., the state of charge of the battery at which the engine will be started to allow the battery charge to be replenished, in accordance with vehicle location. The engine will also be started when the vehicle is within a predetermined distance of a long-term parking location.

Abstract: Methods and systems for determining a state of charge of a battery are provided. A first component of the state of charge is calculated based on a first property of the battery. A second component of the state of charge is calculated based on a second property of the battery. The first component of the state of charge is weighted based on a rate of change of the first property relative to a change of the state of charge. The second component of the state of charge is weighted based on a rate of change of the second property relative to a change of the state of charge. The state of charge is determined based on the first and second weighted components.

Abstract: A system and method for estimating internal parameters of a lithium-ion battery to provide a reliable battery state-of-charge estimate. The method uses a two RC-pair equivalent battery circuit model to estimate the battery parameters, including a battery open circuit voltage, an ohmic resistance, a double layer capacitance, a charge transfer resistance, a diffusion resistance and a diffusion capacitance. The method further uses the equivalent circuit model to provide a difference equation from which the battery parameters are adapted, and calculates the battery parameters from the difference equation.

Abstract: A method for rapidly determining an initial diffusion voltage (Vdiff)initial as a starting point in calculating a diffusion voltage in an electro-chemical cell (e.g., a battery used in an automotive vehicle) includes obtaining a time difference toff between a time when the cell was last turned-OFF and a time when the cell was next turned-ON, selecting a starting diffusion voltage (Vdiff)start based on toff, determining a trial diffusion voltage Vdiff based on a diffusion circuit model and (Vdiff)start, calculating an error voltage Verror=(Vdiff)?|VOFF?VON| where VOFF and VON are cell voltages at turn-OFF and turn-ON respectively, repeating the foregoing determining and calculating steps using for each iteration (Vdiff)start=(Vdiff)previous+Verror until Verror is less than or equal to a first predetermined tolerance amount ?, storing in a memory a value of Vdiff corresponding to the condition Verror??, and setting (Vdiff)initial equal to the just stored value of Vdiff.